Experimental Difficulties Encountered in Testing Air/Water Mixtures
The Tennessee Valley Authority and Voith Hydro, Inc., are conducting a joint research project to study the effects of air admission on hydraulic turbines. Francis turbine models, homologous...
Energy Losses Due to Air Admission in Hydroturbines
Admission of air at the exit of a hydroturbine runner is an attractive technique for raising dissolved oxygen levels downstream of a hydro plant. The air admission, however, is generally...
Numerical Modeling of Air/Water Mixtures for Internal Flows
The Tennessee Valley Authority (TVA) currently is working with several organizations to develop design tools for the aerating hydroturbine. Part of this effort includes the investigation...
Efficiency and Cavitation Effects of Hydroturbine Venting
Volkart and Bohac et al. have summarized much of the past work on aeration of hydroturbine releases to improve downstream water quality. Conventional alternatives for increasing dissolved...
Physical Model of a Floating Trash Boom to Control Aquatic Weeds at the TVA Widows Creek Fossil Plant
The Tennessee Valley Authority (TVA) Widows Creek Fossil Plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce...
Reviewing the Operating Objectives of the TVA Reservoir System
Under the Tennessee Valley Authority's Lake Improvement Plan, approved by the Board of Directors in February 1991, minimum flows will be provided systemwide, the releases...
The Effect of Surface Films on Concentration Fluctuations Close to a Gas/Liquid Interface
Modeling of gas/liquid mass transport requires knowledge concerning the behavior of near-surface concentration fluctuations at clean and film-covered gas/liquid interfaces. Previous measurements...
Measurement of Reaeration Coefficient with the Soluble Solids Probe
The results of analytical and experimental studies are presented, showing that the proposed method for indirect determination of gas transfer coefficients at gas-liquid interfaces, based...
Dissolved Oxygen and Woody Debris: Detecting Sensitive Forest Streams
Early watershed studies showed that timber harvesting and yarding could depress dissolved oxygen in nearby streams when fresh slash entered streams and streamside shade was reduced. State...
Epilimnetic Dissolved Oxygen Content and Surface Water Pump Performance
Surface water pumps have been operated and monitored at TVA's Douglas Dam since 1987. The purpose of these pumps is to improve the dissolved oxygen (DO) content of the hydropower...
Technology Development for Auto-Venting Turbines
Experimentation with venting air into the hydroturbines at Norris Dam has convinced the Tennessee Valley Authority (TVA) that this is a viable method for increasing dissolved oxygen (DO)...
A Simple Empirical Model of Aeration at Navigation Dams
In a study of aeration at 28 dams in the upper Ohio River basin, site-specific least-squares linear regression models were used to describe the dissolved oxygen deficit below each dam...
Oxygen Transfer at Spillways
A relationship for oxygen transfer efficiency, E, at spillways and gated spillways with a hydraulic jump or plunge pool, has been developed from conceptual considerations and fit to measurements...
Sidestream Elevated Pool Aeration Station Design
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is constructing a system of five Sidestream Elevated Pool Aeration (SEPA) stations along the 35.8 mile Calumet River,...
Mechanical Aeration System Design for Reservoir Tailwater Enhancement
Low dissolved oxygen (DO) concentrations in tailraces below hydropower facilities has been identified as a problem at some projects during nongeneration periods. One technique which may...
Experiment on the Efficiency of an Aspirator-Blower Type Aerator
An aspirator-blower type aerator was designed and tested successfully for small lake application. The experiment showed that significant amount of air flow can be generated by the aspirator...
Water Surface Flow and Exchange Induced by a Bubble Plume
Aeration is a common method to increase dissolved oxygen in the water of stratified (or non-stratified) lakes. In this method compressed air is injected at some depth, and gas is transferred...
Oxygen Mass Transfer to Flowing Ground Water Using Oxygen Microbubbles
Mass balance and transfer of oxygen has been studied from oxygen microbubbles to low dissolved oxygen ground water passing through variously configured pilot scale vertical slice test...
Meeting MARPOL Annex V Requirements, A Model for Recreational Ports and Harbors
MARPOL (an abbreviation for marine pollution) is an international agreement to reduce marine pollution globally. It is comprised of five annexes, and the purpose of Annex V is to reduce...
Waste to Energy? The Burning Question
For all their bad press, waste-to-energy plants actually provide a one-two environmental punch�they reduce garbage volume and provide alternative energy. But increasingly, state and local...
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